In the first example, a wishful statement, not a fact, is being expressed;
therefore, were , which we usually think of as a plural verb, is used with the singular it. (Technically, it is the singular subject of the object clause in the subjunctive mood: it were Friday .)
Normally, he raise would sound terrible to us. However, in the second example, where a request is being expressed, the subjunctive mood is correct.
Note: The subjunctive mood is losing ground in spoken English but should still be used in formal speech and writing.